P
OITEVINETAL.
: J
OURNALOF
AOACI
NTERNATIONAL
V
OL
. 92,N
O
. 5, 2009
1511
Table 27. MD1–4 ruggedness tests: accuracy, precision, andHorRat values found for phosphorus insixcertifiedand in-house referencematerialsusing
recommended lines
Material description
-test code
a
Reference
value,mg/kg
b,c
Median,
mg/kg
Recovery,%
P
-value
d
SD
r
,mg/kg
e
SD
iR
,mg/kg
f
RSD
r
,% RSD
iR
,% HorRat
g
Chocolatemilkpowder
MD1
4080±30
4110
101±1
0.61
51
132
1.3
3.2
0.5
MD2
4150
102±1
0.28
62
150
1.5
3.6
0.6
MD3
4140
101±1
0.14
30
49
0.7
1.2
0.2
MD4
4170
102±1
0.07
36
86
0.9
2.0
0.3
Infant cereals
MD1
430±21
4418
102±1
0.10
101
155
2.3
3.5
0.5
MD2
4508
104±1
0.01
75
161
1.7
3.6
0.6
MD3
4384
102±1
0.10
57
87
1.3
2.0
0.3
MD4
4321
100±1
0.97
77
97
1.8
2.3
0.4
Cornbran
MD1
171±6
151
88±6
0.06
4
23
2.7
15.1
1.4
MD2
163
95±6
0.45
4
24
2.4
15
1.4
MD3
169
99±4
0.30
2
9
1.0
5.3
0.5
MD4
116
68±6
0.001
4
27
3.3
23.4
2.1
Dieteticmilkpowder 1
MD1
3080±11
3095
101±1
0.41
29
44
0.9
1.4
0.2
MD2
3170
103±1
0.08
27
123
0.8
3.9
0.6
MD3
3133
102±1
0.06
17
61
0.5
1.9
0.3
MD4
3111
101±1
0.21
45
67
1.4
2.2
0.3
Pet food
MD1
4510±40
449
100±1
0.60
28
49
0.6
1.1
0.2
MD2
464
103±1
0.11
30
173
0.6
3.7
0.6
MD3
454
101±1
0.56
36
78
0.8
1.7
0.3
MD4
453
101±1
0.60
66
84
1.4
1.9
0.3
Nonfatmilkpowder
MD1
10600±100
1059
100±1
0.90
109
136
1.0
1.3
0.2
MD2
1088
103±2
0.12
156
367
1.4
3.4
0.6
MD3
1044
99±1
0.20
81
153
0.8
1.5
0.3
MD4
1040
98±1
0.12
66
176
0.6
1.7
0.3
a
Ruggedness test usingdifferentmicrowavedigestionsystemsand ICP-AESequipment (Table1).
b
SDexpressedashalf of stateduncertainty (NISTandLGCcertifiedmaterials) givenas95%confidence interval.
c
SDexpressedasa reproducibilitySD(in-house referencematerials) calculatedaccording to robust statistics (29).
d
Statisticevaluationof robust
t
-test: Satisfactory result (
P
>0.05); questionable result (0.01<
P
<0.05); unsatisfactory result (
P
<0.01).
e
SD
r
=SDof repeatability.
f
SD
iR
=SDof intermediate reproducibility.
g
HorRat =RatiousingRSD
iR
andHorwitzdenominator according to ref. 32.
MTE-01
FORWORKINGGROUP/ERPUSEONLY
DONOTDISTRIBUTE
